In recent years, the number of crimes has been only increasing on a global scale, and a more affordable and more effective security system has been strongly desired all over the world to protect a housing, an automobile, a personal computer and the like from a sneak thief, an illegal intruder, a hacker and the like. However, most of conventional security systems generally have a relatively complex structure, and despite having the relatively complex structure, their presences are often quickly perceived visually by an intruder, so that the security systems are often made ineffective before activated. Further, the security systems are generally managed by a security manager, and the settings of the security systems cannot be changed as required by a user, for example. Accordingly, for example, in the case of a rental apartment, a resident of the rental apartment cannot help but rely on a troublesome measure such as replacement of the key to protect the residence from ex-residents and contractors.
Patent Literature 1
Japanese Patent Laid-Open Publication No. 518759/2002 (discloses an example of conventional security systems.)